GB2141770A - Framework gate - Google Patents

Abstract

A grid-type framework eg an agricultural field gate 1 is formed from a plurality of dismountable die cast aluminum frame units 3,4,5,6,7,8 each unit comprising at least two transversely disposed frame members and each including a male spigot and/or a female socket for force fitting in the complementary male or female part of an adjacent frame unit. <IMAGE>

Description

SPECIFICATION A grid-type framework The invention relates to a grid-type framework and in particular to agricultural field gates.

Conventional agricultural field gates are generally fabricated from light tubular steel.

The major disadvantage of such gates is that they do not have a long life in use, usually failing from rusting inside a period of twenty years. In addition, they are time consuming to fabricate and are relatively expensive.

Similar comments apply to other grid-type frameworks such as railings, doors and windows, circular or plain feeders and other similar structure.

This invention is directed towards providing a grid-type framework which will overcome these difficulties.

According to the invention there is provided a grid-type framework comprising a plurality of dismountable frame units, each unit comprising at least two transversely disposed interconnected frame members, the frame members having a male or female part on one side of the point of interconnection for mating with a complementary male or female part of an adjacent frame unit.

In one particularly preferred embodiment of the invention the frame members of each unit are transversely disposed and intersect intermediate their ends to form the male or female part on one side of the point of intersection.

In one embodiment of the invention the male part is a force fit in the female part.

In another embodiment of the invention the male and female parts are formed with complementary interengagable formations.

The formations may, for example, constitute a latch and latch retainer mechanism. Alternatively, the formations may comprise a snap-in connection.

Further, the formations may comprise a plurality of serrations on one part interengagable with complementary serrations on the other part.

In one embodiment of the invention the frame unit is an intermediate frame unit comprising three intersecting frame members, namely a first leg intersecting a second leg and extending to cross a third leg, the second and third legs extending substantially parallel to each other and.perpendicularto and on both sides of the first leg to form male or female parts.

Preferably the first leg also extends beyond the second andthird legs to form a male or female part.

In another embodiment of the invention the frame unit is a corner unit comprising a first frame member cranked intermediate its ends to form a corner section and a second member extending transversely intermediate the ends of the first member. Preferably, the second member includes a bolt guide means. Usually the bolt guide means comprises a pair of aligned latch bolt guide lugs.

In a further embodiment of the invention the frame unit comprises a heel bar unit comprising a first arm, a second arm and a third arm, the second and third arms extending substantially parallel to each other and transversely of the first arm from points of intersection intermediate the ends of the first arm.

In a preferred embodiment of the invention each unit is die cast from an aluminium material. Specifically each member of each unit is alternately cored out from opposed sides.

In one particularly preferred embodiment of the invention the framework comprises a gate. Preferably, the gate is formed from two oppositely directed corner units, two oppositely directed heel bar units and a plurality of intermediate units interconnecting the corner units and the heel bar units.

In one aspect the invention provides a gate comprising a plurality of dismountable frame units, each frame unit having a male orfemale part for mating with a complementary male or female part of an adjacent frame unit.

In another aspect the invention provides a frame unit having three intersecting frame members, namely a first leg intersecting a second leg and extending to cross over a third leg, the second and third legs extending substantially parallel to each other and perpendicular to and on both sides of the first leg to form male or female parts for mating with a complementary male or female part of another frame unit. Preferably the first leg also extends beyond the second and third legs to form a male or female part.

In another aspect the invention provides a frame unit comprising a front corner unit having a first frame member cranked intermediate its ends to form a corner section and a second frame member extending transversely intermediate the ends of the first member. Preferably the second member includes a bolt guide means. Usually the guide means comprises a pair of aligned latch bolt guide lugs.

In a further aspect the invention provides a frame unit comprising a heel bar unit having a first arm, a second arm and a third arm, the second and third arms extending substantially parallel to each other and transversely of the first arm from points of intersection intermediate the ends of the first arm.

In a preferred embodiment of these aspects of the invention each unit is die cast from aluminium material. Typically each member of each unit is alternately cored out from opposed sides.

The invention also provides a die for forming such frame units.

The invention will be more clearly understood from the following description thereof given by way of example only with reference to the accompanying drawings in which: Figure l is a schematic assembly lay-out of a gate according to the invention, Figure 2 is a schematic view showing the gate assembled, Figure 3 is an exploded perspective partially cut-away view of portion of the gate of Figure 2 showing one construction of joint between adjacent frame units, Figure 4 is a sectional view of the joint of Figure 3, assembled, Figure 5 is a perspective view of one upper intermediate unit forming part of the gate of Figure 1, Figure 6 is a side elevation of the unit of Figure 5 on an enlarged scale, Figure 7 is a longitudinal sectional viewthrough the top leg of the unit of Figure 6, Figure 8 is an outline side view of a lower intermediate unit similar to the unit of Figure 5, Figure 9 is an outline side view of a front corner unit forming part of the gate of Figure 2, Figure 70 is an outline side view of another front unit, Figure 7 7 is an outline side view of an upper heel bar unit forming part of the gate of Figure 2, Figure 12 is an outline side view of a lower heel bar unit, Figure 13 is an exploded perspective view of another joint for use with the units of Figures 5 to 12, Figure 14 is an exploded perspective view of another construction of joint for use with the units of Figures 5 to 12, Figures 15 to 17 are plan views on a reduced scale showing the layout of dies for die casting the units of Figures 5 to 12.

Referring to the drawings and initially to Figures 1 to 11 thereof, there is illustrated a grid type framework in this case an agricultural field gate indicated generally by the reference numeral 1 formed from a plurality of dismountable units 2 each of which is die cast from aluminium material. There are six types of units namely, a top front corner unit 3, a bottom front corner unit 4, nine top intermediate units 5, nine bottom intermediate units 6, a top heel bar unit 7 and a bottom heel bar unit 8. A latch bolt 9 is also provided and in use is slidably mounted on the top front unit 3.As will be described in more detail below each of the units comprises at least two transverse members which intersect intermediate their ends to form on one side of the point of intersection a male 10 orfemale 11 part for mating with a complementary male 10 or female 11 part of an adjacent unit on assembly of the gate 1.

In detail, and referring particularly to Figures 3 and 4 each male part 10 comprises a spigot 13 having a forwardly projecting latch 14 engagable over a complementary latch retainer 15 in a socket 16 forming the female part 11.

Each of the members are cored out alternately from opposed sides to form a plurality of slots 27 spaced-apart along the members. It will be appreciated that the coring out is shown for illustrative purposes only and that any suitable constructional members may be employed, for example, hollow sections. The particular advantage of the coring out however, is that the units may be relatively easily die cast Referring particularly to Figures 5 to 7 each top intermediate unit 5 comprises three intersecting legs namely, a first leg 20, and second leg 21 and third leg 22 which are substantially parallel and extend transversely of the first leg 20. The second leg 21 intersects the first leg 20 to form a male part 10 on one side of the point of intersection 24 and a female part 11 on the other side of point of intersection.The third leg 22 crosses the first leg 20 intermediate its ends to form another male part 10 on one side of the point of intersection 26 and another female part 11 on the other side of the point of intersection 26. A male part 10 is also provided at the free end of the first leg 20.

Referring particularly to Figure 8 a bottom inter mediate unit 6 of similar construction to the top intermediate unit 5 described above is illustrated, like parts being assigned the same reference numer als. This unit is essentially a mirror image of the top front unit with the exception that instead of a male part at the free end of the first leg 20 a female part 11 is provided.

Referring to Figure 9 the top front corner unit 3 comprises a first member 40 cranked intermediate its ends at 41 to form a corner section and a second member 42 extending transversely intermediate the ends of the first member from a point of intersection 43 with the first member 40. Each of the free ends of the first member 40 and second member 42 are formed with female parts 11. The bolt 9 is mounted on the second member 42 and is slidable in bolt guides 45. A rectangular depression 46 is provided along the member 42 sized to be a force fit with the bolt 9. In use, the bolt 9 is inserted through the depression 46 and guides 45 on assembly and can only be removed by forcing it back through the depression 46.

Referring to Figure 10 the bottom front corner unit 4 is again essentially a mirror image of the top front corner unit 3 described above with reference to Figure 8 and like parts are assigned the same reference numerals. In this case, a male spigot part 10 is provided at the innermost end of the first member 40.

Referring to Figure 11 the top heel bar unit 7 is formed from three intersecting arms namely, a first arm 50 a second arm 51 and a third arm 52. The second and third arms 51,52 are spaced-apart and extend transversely in a direction substantially perpendicular to the first arm 50 intermediate the ends thereof. Male spigot parts 10 are provided at the free ends of the first and third arms 51, 52 and the lowermost end, in use of the first arm 50. A female part 11 is provided at the opposite end of the arm 50.

Referring to Figure 12 the bottom heel bar unit 8 is essentially a mirror image of the top heel bar unit described above with reference to Figure 10 and like parts are assigned the same reference numerals. In this case, a female part 11 is provided at both free ends of the first member 50.

Referring to Figure 13 there is illustrated an alternative construction of joint 60 between the members of adjacent units. The joint 60 comprises a male part 61 formed from four depending staggered rectangular lugs 62 and a complementary-shaped female part 63 comprising four spaced-apart slots 64 into which the lugs 62 are fitted on assembly. The joint 60 is essentially a vertical joint. The advantage of the vertical joint is that the joint is achieved without any metal to metal contact in the die cavity parts.

Referring to Figure 14 there is illustrated another construction of joint 70 in this case comprising a plurality of serrations 72 provided around the periphery of a male spigot part 71 for interengagement with complementary serrations 73 around the inner periphery of a female socket part 74. The serrated area and depth of the serrations may be progressively incrased to achieve a desired joint strength. Further, adhesives may be incorporated in the joint if required. The particular advantage of this type of joint is in the position locking provided by the large area of contact between the parts.

Figures 15 to 17 illustrate the layout of dies for casting respectively the top and bottom intermediate units 5,6, the top and bottom front units 3,4, and the top and bottom heel bar units 7, 8 and bolt 9. Each die is of conventional construction comprising a die holder 81, die cavity 82, spreader block 83 and shot sleeve opening 84.

The units are designed to be made in a technically simple die cavity which is relatively simple to manufacture and maintain.

It will be noted that the gate can be easily manufactured from the output of three dies. It will also be noted that there are no die parts moving at an angle to a line of opening of the die halves and consequently no side cores are required.

The same die holder may be used for the three dies, with interchangable inserts and some inserts common.

The principal advantage of the invention is that it provides a gate which is simple and cheap to manufacture and has a long life in use without any considerable reduction in the strength over and above conventional tubular steel gates. In addition, the gate is lightweight, and can be sold in a kit-form for easy assembly by unskilled workmen, on site.

I have found in experimenting with the joints described above that when a joint is made with a certain pressure it requires about the same pressure to separate the parts if the separation is carried out immediately. However, I have found that if the separation is carried out after an interval, in most cases of as little as one day, the force needed to separate the parts increases significantly. I have not carried out detailed analysis however it appears that the force required increases approximately twofold.

While I have not investigated this in detail I would tentatively attribute this phenomenon to the fact that aluminium forms an oxide layer very quickly and when the two surfaces being joined meet a force fitting the oxide layer is at least partially cleaned off.

However, once the joint has been made the oxide layer reforms at least to some extend as a common layer over part, at least, of the joint, resulting in a form of weld.

It will be appreciated that while the invention has been described with reference to a particular construction of gate it may be applied to any grid-type framework including, railings, circular and plain cattle feeders, doors, windows or any other similar frameworks.

It will also be apprecieated that varying sizes and different constructions of frameworks may be made by adding or omitting frame units, as desired.

It will be appreciated that any suitable construction of joint may be used for joining the units.

Generally, the joint is of a force fit type, however, if a sufficient retaining force is not available the joint can be reinforced by using an adhesive, by welding, rivetting, bolting or crimping the joint. It will be noted that there is metal to metal contact across each joint to minimise any movement across the joint.

The design of joint is such that the desired fit can be achieved by initial manufacture to produce a free fit and subsequent removal of metal from easy accessible die parts to produce the desired force fit, so that the desired fit may be approached in small increments, if required.

It will also be appreciated that while the specific embodiments of the invention has referred to units of die cast aluminium, any suitable material of construction may be used. Thus, any suitable grade of aluminium alloy particularly those with a silicone content may be used. The alloy may also contain a small amount of sodium which is added to the melt to increase the ductility of the final cast product. The aluminium gate illustrated weighs approximately 30 Ibs. In some applications a heavier gate may be desirable and this can be achieved using the same dies with a zinc material. If on the other hand a lighter gate is required this can be produced with a minor modification from magnesium material.

Claims (30)

1. A grid-type framework comprising a plurality of dismountable frame units, each unit comprising at least two transversely disposed interconnected frame members, the frame members having a male or female part on one side of the point of interconnection for mating with a complementary male or female part of an adjacent frame unit.

2. Aframework as claimed in claim 1 in which the frame members of each unit are transversely disposed and intersect intermediate their ends to form the male or female part on one side of the point of intersection.

3. A framework as claimed in claim 1 or 2 in which the male part is force fit in the female part.

4. A framework as claimed in claim 1 or 2 in which the male and female part are formed with complementary interengagable formations.

5. A framework as claimed in claim 4 in which the formations constitute a latch and latch retainer mechanism.

6. A framework as claimed in claim 4 in which the formations comprise a snap-in connection.

7. A framework as claimed in claim 4 in which the formations comprise a plurality of serrations on one part interengagable with complementary serrations on the other part.

8. A framework as claimed in any of claims 1 to 7 in which the frame unit is an intermediate unit comprising three intersecting frame members, namely a first leg intersecting a second leg and extending to cross a third leg, the second and third legs extending substantially parallel to each other and perpendicular to and on both sides of the first leg to form male or female parts.

9. A framework as claimed in claim 8 in which the first leg also extends beyond the second and third legs to form a male or female part.

10. A framework as claimed in any of claims 1 to 17 in which the frame unit is a corner unit comprising a first frame member cranked intermediate its ends to form a corner section and a second member extending transversely intermediate the ends of the first member.

11. A framework as claimed in claim 10 in which the second member includes a bolt guide means.

12. Aframeworkasclaimed in claim 11 in which the bolt guide means comprises a pair of aligned latch bolt guide lugs.

13. A framework as claimed in any of claims 1 to 7 in which the frame unit is a heel bar unit comprising a first arm, a second arm and a third arm, the second and third arms extending substantially parallel to each other and transversely of the first arm from points of intersection intermediate the ends of the first arm.

14. A framework as claimed in any of claims 1 to 13 in which each frame unit is die cast from an aluminium material.

15. A framework as claimed in any of claims 1 to 14 in which each member of each unit is alternately cored out from opposed sides.

16. A framework as claimed in any of claims 1 to 15 in which a plurality of units are interengaged to form a gate.

17. Aframework as claimed in claim 16 in which the gate comprises two oppositely directed corner units, two oppositely directed heel bar units and a plurality of intermediate units interconnecting the corner units and the heel bar units.

18. A gate comprising a pluralityofdismountable frame units, each frame unit having a male or female part for mating with a complementary male or female part of an adjacent frame unit.

19. A frame unit for use in a grid-type framework comprising an intermediate frame unit having three intersecting frame members, namely a first leg intersecting a second leg and extending to cross over a third leg, the second and third legs extending substantially parallel to each other and perpendicularto and on both sides of the first leg to form male or female parts, for mating with a complementary male or female part of another frame unit.

20. A frame unit as claimed in claim 19 in which the first leg also extends beyond the second and third legs to form a male or female part.

21. A frame unit for use in a grid-type framework comprising a front corner unit having a first frame member cranked intermediate its ends to form a corner section and a second frame member extending transversely intermediate the ends of the first member.

22. A frame unit as claimed in claim 21 in which the second member includes a bolt guide means.

23. A frame unit as claimed in claim 22 in which the guide means comprises a pair of aligned latch bolt guide lugs.

24. Aframe unit for use in a grid-type framework comprising a heel bar unit having a first arm, a second arm and a third arm.

25. A frame unit as claimed in any of claims 19 to 24which is die castfrom an aluminium material.

26. A frame unit as claimed in any of claims 19 to 25 in which each member of each unit is alternately cored out from opposed sides.

27. A die for forming a frame unit as claimed in any of claims 19 to 26.

28. A grid-type framework substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

29. A gate substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

30. A frame unit substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.